Trump doesn't know whether he's heard of a Category 5 storm

US President Donald Trump said on Sunday that he's "not sure that ever even heard of a Category 5" hurricane, despite four such storms having threatened the US since he took office.

"We don't even know what's coming at us. All we know is it's possibly the biggest. I have -- I'm not sure that I've ever even heard of a Category 5. I knew it existed. And I've seen some Category 4's -- you don't even see them that much," Trump said at a briefing with officials in Washington DC.

"But a Category 5 is something that -- I don't know that I've ever even heard the term other than I know it's there. That's the ultimate, and that's what we have unfortunately," he added.

Hurricane Dorian tore across the Bahamas on Sunday as a historically powerful hurricane, officials said, leaving scenes of devastation in its path.

When the storm made landfall on Great Abaco Island, east of Miami, on Sunday at 2 p.m., Dorian's maximum sustained winds were 185 mph — an Atlantic hurricane record matched only by a storm that struck the Florida Keys in 1935, the National Hurricane Center said.

Leigh Lamattina-Davis, a resident of Marsh Harbor, a town of roughly 6,000 on Great Abaco, described the direct hit as "total devastation."

"I am lucky to have half a house", she said in a text message with NBC News. "My neighbours have had their properties demolished."